Physical Sciences and Mathematics Commons^™

Studies On The Preparation Of Nanophase Electrode Materials And Its Electrochemical Properties(Ⅲ)—Performance Of Nm-Γ-Mno2 Obtained By Microemulsion Method, Ling Liu, Xi Xia

Journal of Electrochemistry

A nanophase MnO₂ was synthesized using w/o microemulsion as reation media, The most favorable experiment conditions for the preparation of nm MnO₂ were researched. XRD,TEM,AC impedance, cyclic voltammetry etc. examinations were used to characterize the sample comparison with the classical MnO₂ (I.C.No.1EMD,electrolytic manganese dioxide). Sample shows that the crystal styucture of the synthesized samples are mainly γ-MnO₂, with average particle size in the nanometer as shown by TEM. It was found that the discharge capacity of nm MnO₂ obtained is significantly higher than that of the I.C.No.1 EMD.

Electrooxidation Of Benzene To Benzoquinone In A Packed Bed Reactor, Xin-Sheng Zhang, Ping Ding, Ying-Chun Dai, Wei-Kang Yuan

Journal of Electrochemistry

A packed electrode reactor was used to oxidize to benzoquinone. Anode bed of the reactor has a size of 10～30 mm×450 mm×50 mm(thickness×length×width),and was packed porous lead alloy. A dispersion of benzene in 1 mol/L aqueous sulfuric acid was passed through the reactor. Current efficiency for benzoquinone generation is 62.9% at optimal operating condition: velocity of electrolyte flow, 0.19 ms ^-1 ;current, 10 A; thickness of anode bed, 10 mm, and percentage of benzene, 24%.

Detection Of Intergalactic Red-Giant-Branch Stars In The Virgo Cluster, Henry C. Ferguson, Ted Von Hippel, Nial R. Tanvir

Publications

It has been suspected for nearly 50 years that clusters of galaxies contain a population of intergalactic stars, ripped from galaxies during cluster formation or when the galaxies’ orbits take them through the cluster center. Support for the existence of such a population of free-floating stars comes from measurements of the diffuse light in clusters and from recent detections of planetary nebulae with positions and/or velocities far removed from any observed cluster galaxy. 10 , 11 But estimates for the mass of the diffuse population and its distribution relative to the galaxies are still highly uncertain. Here we report the …

Study Of Proton Exchange Membrane Fuel Cells(Pemfc), Shan-Hai Ge, Bao-Lian Yi, Hong-Fen Xu, Ming Han, Zhi-Gang Shao

Journal of Electrochemistry

The electrode kinetic parameters for proton exchange membrane fuel cells(PEMFC) were investigated by measuring the relations of cell potential and current density. An experimental stack of PEMFC which can be operated at E cell =0.7V, I =0.55A/cm² steadily is presented, and the effects of electrode structure and operation conditions such as temperature, pressure, humidification, flow rate on the performance of PEMFC are discussed.

Putative Light Scalar Nonet, Joseph Schechter, Deirdre Black, Amir H. Fariborz, Francesco Sannino

Physics - All Scholarship

We investigate the "family" relationship of a possible scalar nonet composed of the a_0(980), the f_0(980) and the \sigma and \kappa type states found in recent treatments of \pi\pi and \pi K scattering. We work in the effective Lagrangian framework, starting from terms which yield "ideal mixing" according to Okubo's original formulation. It is noted that there is another solution corresponding to dual ideal mixing which agrees with Jaffe's picture of scalars as qq\bar q \bar q states rather than as q\bar q states. At the Lagrangian level there is no difference in the formulation of the two cases (other …

Integrating The Nation's Environmental Monitoring And Research Networks And Programs, James R. Gosz, Pete Murdoch

Long Term Ecological Research Network

An Exercise to Demonstrate the Value of Index Areas in a National Network: A Report Prepared for the Office of Science and Technology Policy (OSTP).

The Environmental Monitoring Team, a team of Federal scientists and program managers, was convened by the CENR Steering Committee and given the charge "to develop a national framework for integration and coordination of environmental monitoring and related research through collaboration and building upon existing networks and programs". Two of the recommendations for a National Environment Monitoring Framework were; 1) evaluate alternatives for selecting the number and distribution of "index areas", including stratification by ecoregion in …

Quadrilaterals Subdivided By Triangles In The Hyperbolic Plane, Dawn M. Haney, Lori T. Mckeough

Mathematical Sciences Technical Reports (MSTR)

In this paper, we consider triangle-quadrilateral pairs in the hyperbolic plane which “kaleidoscopically” tile the plane simultaneously. These tilings are called divisible tilings or subdivided tilings. We restrict our attention to the simplest case of divisible tilings, satisfying the corner condition, in which a single triangle occurs at each vertexof the quadrilateral. All possible such divisible tilings are catalogued as well as determining the minimal genus surface on which the divisible tiling exists. The tiling groups of these surfaces are also determined.

Correlation Function Formulation For The State Selected Total Reaction Probability, Sophya Garashchuk, David J. Tannor

Faculty Publications

Investigates the correlation function formulation for the state selected total reaction probability. Discussion of the wave packet propagation; Derivation of the correlation function expression for the N[sub alpha](E); Application of quantum-mechanical and Herman-Kluk propagation methods.

Semi-Automated Extraction Of Digital Objective Prism Spectra, Coryn A.L. Bailer-Jones, Ted Von Hippel, Mike Irwin

Publications

We describe a method for the extraction of spectra from high dispersion objective prism plates. Our method is a catalogue driven plate solution approach, making use of the Right Ascension and Declination coordinates for the target objects. In contrast to existing methods of photographic plate reduction, we digitize the entire plate and extract spectra off-line. This approach has the advantages that it can be applied to CCD objective prism images, and spectra can be re-extracted (or additional spectra extracted) without having to re-scan the plate. After a brief initial interactive period, the subsequent reduction procedure is completely automatic, resulting in …

Search For Selectron And Squark Production In E+P Collisions At Hera, J. Breitweg, M. Derrick, D. Krakauer, S. Magill, D. Mikunas, B. Musgrave, J. Repond, R. Stanek, R. L. Talaga, R. Yoshida, H. Zhang, Margarita C. K. Mattingly, F. Anselmo, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, G. Cara Romeo, G. Castellini, L. Cifarelli, F. Cindolo, A. Contin, N. Coppola, M. Corradi, S. De Pasquale, P. Giusti, G. Iacobucci, G. Laurenti

Faculty Publications

We have searched for the production of a selectron and a squark in e+p collisions at a center-of-mass energy of 300 GeV using the ZEUS detector at HERA. The selectron and squark are sought in the direct decay into the lightest neutralino in the framework of supersymmetric extensions to the Standard Model which conserve R-parity. No evidence for the production of supersymmetric particles has been found in a data sample corresponding to 46.6 pb-1 of integrated luminosity. We express upper limits on the product of the cross section times the decay branching ratios as excluded regions in the parameter space …

The Tubular Phase Of Self-Avoiding Anisotropic Crystalline Membranes, Mark Bowick, Alex Travesset

Physics - All Scholarship

We analyze the tubular phase of self-avoiding anisotropic crystalline membranes. A careful analysis using renormalization group arguments together with symmetry requirements motivates the simplest form of the large-distance free energy describing fluctuations of tubular configurations. The non-self-avoiding limit of the model is shown to be exactly solvable. For the full self-avoiding model we compute the critical exponents using an epsilon-expansion about the upper critical embedding dimension for general internal dimension D and embedding dimension d. We then exhibit various methods for reliably extrapolating to the physical point (D=2,d=3). Our most accurate estimates are nu=0.62 for the Flory exponent and zeta=0.80 …

Applications Of Parallel I/O, Ron Oldfield, David Kotz

Computer Science Technical Reports

Scientific applications are increasingly being implemented on massively parallel supercomputers. Many of these applications have intense I/O demands, as well as massive computational requirements. This paper is essentially an annotated bibliography of papers and other sources of information about scientific applications using parallel I/O. It will be updated periodically.

Collaborative Decision Support Systems For Facility Management, Arthur J. Chapman, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

Agent-based collaborative decision support is a methodology of utilizing domain specific intelligent systems, interacting in a common environment, to partner with one or more human decision makers to reach a consensus solution to a complex problem. An example is the recently developed Collaborative Infrastructure Assessment Tool (CIAT) that provides a collaborative planning facility management tool in support of military pier and port management. This methodology is applicable to many similar dynamic facility management problems where the complexity of issues and the number of decision makers result in the need for domain specific agents, a common view of the data, and …

Detergent-Salt Resistance Of Lap2Α In Interphase Nuclei And Phosphorylation-Dependent Association With Chromosomes Early In Nuclear Assembly Implies Functions In Nuclear Structure Dynamics, Thomas Dechat, Josef Gotzmann, Andreas Stockinger, Crafford A. Harris, Mary Ann Talle, John Siekierka, Roland Foisner

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

Lamina-associated polypeptide (LAP) 2 of the inner nuclear membrane (now LAP2β) and LAP2α are related proteins produced by alternative splicing, and contain a common 187 amino acid N-terminal domain. We show here that, unlike LAP2β, LAP2α behaved like a nuclear non-membrane protein in subcellular fractionation studies and was localized throughout the nuclear interior in interphase cells. It co-fractionated with LAP2β in nuclear lamina/matrix-enriched fractions upon extraction of nuclei with detergent, salt and nucleases. During metaphase LAP2α dissociated from chromosomes and became concentrated around the spindle poles. Furthermore, LAP2α was mitotically phosphorylated, and phosphorylation correlated with increased LAP2α solubility upon extraction …

The Future Of Computing: Cyberspace, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

This paper traces trends in the technological advances of computer and communication systems and examines the promises of the Information Society: global information sharing; and, intelligent decision-support. The technological developments that will lead to the realization of Cyberspace, an information rich environment in which virtual reality capabilities couple directly to the human senses, is explored in terms of five essential components: information processing requirements; communication networks; computing devices (i.e., platforms); hardware and software user-interfaces; and, the meaningful representation of information.

Attention is drawn to the critical role played by information representation in a Cyberspace environment. The author argues …

The Round Table Model: A Web-Oriented, Agent-Based Approach To Decision-Support Applications, Kym J. Pohl, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

Not unlike King Arthur relying on the infamous Round Table as the setting for consultation with his most trusted experts, agent-based, decision-support systems provide human decision makers with a means of solving complex problems through collaboration with collections of both human and computer-based expert agents. The Round Table Framework provides a formalized architecture together with a set of development and execution tools which can be utilized to design, develop, and execute agent-based, decision-support applications. Based on a three-tier architecture, Round Table incorporates forefront technologies including distributed-object servers, inference engines, and web-based presentation to provide a framework for collaborative, agent-based decision …

Measured Stark Widths And Shifts Of Several Niii Sectral Lines: Temperature Dependence, Stevan Djenize, Vladimir Milosavljevic

Articles

Stark parameters (width and shift) of four doubly ionized nitrogen spectral lines, that belong to 3s-3p and 3p-3d transitions (lower multiplets), have been measured in a linear pulsed, low pressure, arc discharge in the nitrogen-oxygen and helium-nitrogen-oxygen plasmas in a (30 000 - 54 000) K electron temperature and a (0.75 10²³ - 2.8 10²³) electron density ranges. The measured values have been compared to the existing experimental and calculated data.

Improving Performance On Incremental Compilation Of Java Bytecodes, Tarique Kazi

Honors Capstone Projects and Theses

No abstract provided.

Orientation Of Nickelocene On Ag(100), D. L. Pugmire, C. M. Woodbridge, Marjorie Langell

Marjorie A. Langell Publications

High-resolution electron-energy-loss spectroscopy has been used to study the molecular adsorption of nickelocene, Ni(C₅H₅)₂, on Ag(100). Results indicate that at up to one monolayer coverage, nickelocene adsorbs molecularly with its axis approximately perpendicular to the surface. At very high coverages, the molecular axis is not exclusively oriented along the surface normal. This is possibly due to randomization of the metallocene orientation as multilayers are formed.

Production Of Energy-Dependent Time Delays In Impulsive Solar Flare Hard X-Ray Emission By Short-Duration Spectral Index Variations, Ted N. La Rosa, Steven N. Shore

Faculty Articles

Cross-correlation techniques have been used recently to study the relative timing of solar flare hard X-ray emission at different energies. These studies find that for the majority of the impulsive flares observed with BATSE there is a systematic time delay of a few tens of milliseconds between low (approximate to 50 keV) and higher energy emission (approximate to 100 keV). These time delays have been interpreted as energy-dependent time-of-flight differences for electron propagation from the corona, where they are accelerated, to the chromosphere, where the bulk of the hard X-rays are emitted. We show in this paper that crosscorrelation methods …

United States Patent: Lime Feeding Repellent, Jerrold L. Belant, Richard A. Dolbeer

United States Department of Agriculture Wildlife Services: Staff Publications

Application of lime at a rate of 500 to 1500 kg/ha to plots desired to be protected from damage by avian and mammalian feeders has been shown to be quite effective. The lime may be administered to the plots in any form. Use of either powder or slurry form is preferred.

Highly Enantioselective Hplc Separations Using The Covalently Bonded Macrocyclic Antibiotic, Ristocetin A, Chiral Stationary Phase, K. Helen Ekborg-Ott, Youbang Liu, Daniel W. Armstrong

Chemistry Faculty Research & Creative Works

The macrocyclic glycopeptide, ristocetin A, was covalently bonded to a silica gel support and evaluated as a liquid chromatographic (LC) chiral stationary phase (CSP). Over 230 racemates were resolved in either the reversed-phase mode, the normal-phase mode, or the polar-organic mode. The retention behavior and selectivity of this CSP were examined in each mode. Optimization of separations on this column is discussed. The ristocetin A CSP appeared to be complimentary to other glycopeptide CSPs (i.e., vancomycin and teicoplanin). Column stability was excellent. The CSP was not irreversibly altered when going from one mobile phase mode to another.

Method And Apparatus For Generating And Accelerating Ultrashort Electron Pulses, Donald P. Umstadter, Joon-Koo Kim, Evan Dodd

Donald Umstadter Publications

The invention provides a novel laser-plasma-based source of relativistic electrons; and a method to use laser-driven plasma waves as the basis for the source of electrons. The technique involves a combination of laser beams, which are focused in a plasma. One beam creates a wakefield plasma wave and the other beam alters the trajectory of background electrons, such that they become trapped in the plasma wave and are then accelerated to relativistic velocities, preferably in a distance less than a millimeter. In another embodiment, the second beam removes electrons from atomic ions previously generated by the first beam thereby providing …

Spectroscopy Of Charge-Coupled Devices, Lars Mündermann

Dissertations and Theses

A systematic study of persistent, or residual, images occurring in CCD imagers and a systematic study of dark current generation in CCD imagers are presented. These effects are a source of unwanted signal in frames, and should be considered where very exact, low light-level signal processing is necessary. For both studies explanatory models and statistical analysis techniques have been developed which enable the derivation of the densities and the characteristic energies. Furthermore the importance of understanding these phenomena in the context of today's low light-level imaging is discussed.

Impurity sites are found to be responsible for residual images. Photoelectrons are …

Coronal Mass Ejections, Magnetic Clouds, And Relativistic Magnetospheric Electron Events: Istp, D. N. Baker, T. I. Pulkkinen, X. Li, S. G. Kanekal, J. B. Blake, R. S. Selesnick, M. G. Henderson, G. D. Reeves, Harlan E. Spence, G. Rostoker

Physics & Astronomy

The role of high-speed solar wind streams in driving relativistic electron acceleration within the Earth's magnetosphere during solar activity minimum conditions has been well documented. The rising phase of the new solar activity cycle (cycle 23) commenced in 1996, and there have recently been a number of coronal mass ejections (CMEs) and related “magnetic clouds” at 1 AU. As these CME/cloud systems interact with the Earth's magnetosphere, some events produce substantial enhancements in the magnetospheric energetic particle population while others do not. This paper compares and contrasts relativistic electron signatures observed by the POLAR, SAMPEX, Highly Elliptical Orbit, and geostationary …

On The Dynamics Of Stochastic Differential Systems (The Seventh Vilnius Conference On Probability Theory And Mathematical Statistics), Salah-Eldin A. Mohammed

Miscellaneous (presentations, translations, interviews, etc)

We outline proofs of two stable-manifold theorems for stochastic differential systems with and without memory. The results are joint work with Michael Scheutzow.

Agricultural Water Management In The Missippi Delta Region Of Arkansas, H. Don Scott, James A. Ferguson, Linda Hanson, Todd Fugitt, Earl Smith

AAES Research Reports and Research Bulletins

Agriculture is the largest use of soil and water resources in eastern Arkansas. This bulletin summarized the recent historical use of soil and water by agriculture and the impact of irrigation on yields of rice, soybeans and cotton. The experiments conducted in the field to quantitatively schedule irrigations of crops are summarized. The results show the close relationship between the irrigation of crops and the extraction of water from the Alluvial Aquifer. The implications of this relationaship for the future are discussed.

The John Muir Newsletter, Fall 1998, The John Muir Center For Regional Studies

Muir Center Newsletters (1981-2015)

Volume 8, Number 4 . I Fall 1998 NEWSLETTER The Muir Renaissance in Scotl by Graham White (Editor's note: A leading voice in the Scottish effort to wkdiscover John Muir, Graham White wrote the introduction to the Canongate collection of Muir's wilderness essays, and is completing a second volume of Muir Writings for that publisher. He can be reached at Brox- mouth Gardens, Dunbar, Scotland EH42 Iqw, or by e-mail at 101320.5 [email protected].) W. he John Muir Newsletter has invited me to outline the resurgence of interest in John Muir in the land of his birth, and to clarify various …

Ultrafast Phenomena: A Laboratory Experiment For Undergraduates, T. D. Donnelly, Carl H. Grossman

Physics & Astronomy Faculty Works

We present a set of experiments that introduce students to ultrafast science. We discuss the relationship between the description of an ultrashort laser pulse in the frequency domain and the time domain. Using experimental results we demonstrate that this relationship is constrained by the lower limit of the Heisenberg uncertainty principle. Students carrying out the experiments will become familiar with ultrafast techniques, such as autocorrelation and laser cavity design, as well as various other concepts such as dispersion, Fourier transformation, interference, and nonlinear optics. (C) 1998 American Association of Physics Teachers.

Parity Nonconservation In Neutron Resonances In 238u, Bret E. Crawford, J D. Bowman, P P J. Delheij, C M. Frankle, M Iinuma, J N. Knudsen, L Y. Lowie, A Masaike, Y Matsuda, G E. Mitchell, S I. Penttila, H Postma, N R. Roberson, S J. Seestrom, E I. Sharapov, Sharon L. Stephenson, Y-F Yen, V W. Yuan

Physics and Astronomy Faculty Publications

Parity nonconservation (PNC) was studied for 24 p-wave neutron resonances in ²³⁸U from 10 to 300 eV by measuring the helicity dependence of the total neutron cross section with an improved experimental apparatus. Six resonances show statistically significant (greater than 2.9σ) parity violation. An analysis treating the PNC matrix elements as random variables yields a root-mean-square PNC matrix element M=0.67_-0.16^+0.24 meV. The corresponding weak spreading width Γ_w=(1.35_-0.64^+0.97)×10^-7 eV.